Yin Chen, bitter and pungent in flavor, slightly cold in nature. It has the effect of clearing dampness and heat, relieving bile and jaundice (dredging the evil qi of the biliary tract and eliminating jaundice). It is used for treating jaundice with low urine output, dampness and warmth (warmth caused by feeling dampness and heat), summer dampness, and itching of wet sores. Adverse effects of Yin Chen: large amount of consumption may cause nausea, vomiting, transient dizziness, arrhythmia. Caution should be exercised in those with blood accumulation and yellowing, and those with blood deficiency and yellowing. The effective dosage of sun-dried Herba Euphrasia in water is limited, generally cannot achieve the therapeutic effect, if you want to achieve the desired effect, it is recommended to carry out regular treatment under the guidance of a doctor. If you feel unwell after drinking the water, it is recommended to stop using it and seek medical advice.